Preparation and Evaluation of a New Lipopolysaccharide-based Conjugate as a Vaccine Candidate for Brucellosis

Objectives: Development of an efficacious vaccine against brucellosis has been a challenge for scientists for many years. At present, there is no licensed vaccine against human brucellosis. To overcome this problem, currently, antigenic determinants of Brucella cell wall such as Lipopolysaccharide (LPS) are considered as potential candidates to develop subunit vaccines. Methods: In this study, Brucella abortus LPS was used for conjugation to Neisseria meningitidis serogroup B outer membrane vesicle (OMV) as carrier protein using carbodiimide and adipic acid-mediated coupling and linking, respectively. Groups of eight BALB/c mice were injected subcutaneously with 10μg LPS alone, combined LPS+OMV and conjugated LPS-OMV on 0 days, 14 days, 28 days and 42 days. Anti-LPS IgG was measured in serum. Results: The yield of LPS to OMV in LPS-OMV conjugate was 46.55, on the basis of carbohydrate content. The ratio for LPS to OMV was 4.07. The LPS-OMV conjugate was the most immunogenic compound that stimulated following the first injection with increased IgG titer of ~5-fold and ~1.3-fold higher than that produced against LPS and LPS in noncovalent complex to OMV (LPS+OMV), respectively. The highest anti-LPS IgG titer was detected 2 weeks after the third injection (Day 42) of LPS-OMV conjugate. The conjugated compound elicited higher titers of IgG than LPS+OMV, that showed a 100-120-fold rise of anti-LPS IgG in mice. Conclusion: These results indicate that our conjugated LPS-OMV can be used as a brucellosis vaccine, but further investigation is required. © 2014

Cinética do crescimento de Borrelia burgdorferi (Spirochaetaceae) em diferentes meios de cultivo Cinetic growth of Borrelia burgdorferi (Spirochaetacease) in different culture media

Estudou-se a cinética de crescimento de Borrelia burgdorferi, por um período de 3 meses, utilizando os seguintes oito meios de cultivo : (1) BSK adicionado de soro de coelho, (2) BSK adicionado de soro de suíno, (3) BSK adicionado de soro de suíno + 5 fluorouracil, (4) PMR, (5) CTB, (6) Dubos, (7) Caldo Brucella e (8) BHI. Todos os meios foram preparados assepticamente e mantidos em tubos de ensaio com capacidade para 10 ml. Para cada meio, o inoculo foi padronizado para conter no início 10² espiroquetas para cada 0,1 ml de cultivo. O monitoramento do crescimento foi feito contando-se o total de espiroquetas em 0,1 ml do meio entre lâmina de microscopia e lamínula com dimen sões de 10x30mm, tendo sido utilizado microscópio de campo escuro. A contagem foi realizada durante 14 semanas, tendo sido diária nos primeiros 12 dias e semanal a partir desta data. Houve crescimento de B. burgdorferi em todos meios testados, com melhor performance para três deles: BSK adicionado de soro de coelho, BSK adicionado de soro de suíno + 5 fluorouracil e meio CTB. Observou-se crescimento de B. burgdorferi a partir da 4ª semana, atingindo o platô de crescimento entre a 8ª e 12ª semanas, quando começou a exaustão do meio de cultivo. Formas císticas de B. burgdorferi foram observadas em todos os meios testados.<br>The cinetic of growth of Borrelia burgdorferi was studied during a 3-month period, using the following 8 culture media: (1) rabbit serum BSK, (2) swine serum BSK, (3) swine serum BSK+5 fluorouracil, (4) PMR, (5) CTB, (6) Dubos, (7) Brucella broth and (8) BHI. All media were prepared aseptically and were maintained in culture tubes of 10 ml capacity. For each medium, the inoculum was standardized to contain initially 10² spirochetes for each 0.1 ml of culture. The growth was monitorized by counting the total number of spirochetes in 0.1ml of medium in a dark field microscope, using a 10x30 mm cover slip. For the first 12 days, counting was done each 24 hours, and afterwards once a week during 14 weeks. There occurred growth of B. burgdorferi in all tested media, with the best performance of three of them: BSK with rabbit serum, BSK swine serum + 5 fluorouracil, and CTB medium. Growth of B. burgdorferi was seen from the 4th week on, reaching its maximum within 8-12 weeks, depleting the culture medium after this time. Cystic forms of B. burgdorferi were observed with all tested media

Non-tuberculous mycobacteria: patterns of isolation. A multi-country retrospective survey36734

OBJECTIVE: To collect data on non-tuberculous mycobacteria (NTM) isolated from clinical laboratories in different countries to establish: 1) whether the isolation of NTM was increasing, 2) which species were increasing, and 3) whether there was any pattern of geographical distribution. DESIGN: In 1996, the Working Group of the Bacteriology and Immunology Section of the International Union Against Tuberculosis and Lung Disease contacted 50 laboratories in different countries for the necessary information. RESULTS: The number of patients reported with NTM was 36099 from 14 countries. Mycobacterium avium complex, M. gordonae, M. xenopi, M. kansasii and M. fortuitum were the five species most frequently isolated. There was a significant upward trend for M. avium complex and M. xenopi. Pigmented mycobacteria predominated in Belgium, the Czech Republic and the Mediterranean coast of Spain. Non-chromogenic mycobacteria were found to be predominant in the area of the Atlantic coast of Brazil and in Turkey, the United Kingdom, Finland and Denmark. CONCLUSIONS: There was an increase in the number of NTM isolated from clinical samples of patients. Isolation of the most frequent species is constantly changing in most of the geographical areas, and newer species are emerging due to better diagnostic techniques to detect and identify NTM</p